U.S. patent application number 14/970799 was filed with the patent office on 2016-04-07 for ablation techniques for the treatment of atrial fibrillation.
The applicant listed for this patent is A. Jason Mirabito, Omer Peled. Invention is credited to A. Jason Mirabito, Omer Peled.
Application Number | 20160095656 14/970799 |
Document ID | / |
Family ID | 49004097 |
Filed Date | 2016-04-07 |
United States Patent
Application |
20160095656 |
Kind Code |
A1 |
Peled; Omer ; et
al. |
April 7, 2016 |
ABLATION TECHNIQUES FOR THE TREATMENT OF ATRIAL FIBRILLATION
Abstract
A catheter device provides a balloon structure and a side-firing
laser lumen within the balloon to create lesions in the pulmonary
vein (PV) in the treatment of atrial fibrillation. Mounted on the
balloon so as to contact the PV when the balloon is inflated are
one or more electrodes which may be used in a measurement mode, a
treatment mode, or both.
Inventors: |
Peled; Omer; (Haifa, IL)
; Mirabito; A. Jason; (Derry, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Peled; Omer
Mirabito; A. Jason |
Haifa
Derry |
NH |
IL
US |
|
|
Family ID: |
49004097 |
Appl. No.: |
14/970799 |
Filed: |
December 16, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14658214 |
Mar 15, 2015 |
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14970799 |
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13772472 |
Feb 21, 2013 |
8992514 |
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14658214 |
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61602653 |
Feb 24, 2012 |
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Current U.S.
Class: |
606/26 ;
606/41 |
Current CPC
Class: |
A61B 2018/00351
20130101; A61B 18/1492 20130101; A61B 5/0538 20130101; A61B
2018/0022 20130101; A61B 2018/2272 20130101; A61B 2018/0016
20130101; A61B 18/24 20130101; A61B 2018/00375 20130101; A61B 18/02
20130101; A61F 2007/126 20130101; A61B 2018/0212 20130101; A61B
2018/00875 20130101; A61B 2018/2244 20130101; A61B 2018/00577
20130101; A61B 2018/00166 20130101; A61B 2018/0262 20130101; A61B
18/20 20130101; A61B 2018/00357 20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14; A61B 18/02 20060101 A61B018/02 |
Claims
1. A device for insertion in the pulmonary vein for the treatment
of atrial fibrillation, the device comprising; a plurality of
substantially parallel apertured lumens having distal and proximal
ends; an inflatable balloon in the vicinity of the distal ends of
the lumens, the apertured lumens having openings in the distal ends
of the lumens within the inflatable balloon; at least one electrode
formed on the balloon, wherein the at least one electrode is
suitable for one or both of measurement and treatment of the
pulmonary vein; the plurality of lumens being suitable for the
introduction and the evacuation of a cryogenic fluid into the
balloon; a controller operatively connected to control the
operation of the at least one electrode and to control a source of
cryogenic fluid wherein, when the inflatable balloon is caused to
be inflated with cryogenic fluid by the controller to treat the
pulmonary vein, the at least one electrode comes into contact with
the pulmonary vein wall, the controller then causing the at least
one electrode to one of or both of measure or treat the pulmonary
vein.
2. The device of claim 1, wherein the controller is further
operable to operate the at least one electrode to measure treatment
parameters after treatment by one or both of cryogenic fluids and
the at least one electrode.
3. The device of claim 1, wherein the at least one electrode is one
or a RF or an ultrasonic electrode.
4. The device of claim 1, further comprising a plurality of
electrodes, the plurality of electrodes being one or more of RF
electrodes, ultrasonic electrodes or a mixture of RF and ultrasonic
electrodes.
5. The device of claim 4, wherein the controller is operable,
responsive to an indication that the treatment is completed, to
cause the introduction of a heated fluid into the balloon to halt
the treatment of the pulmonary vein.
6. The device of claim 4, wherein the controller is operative,
responsive to an indication that the treatment is completed, to
cause an electric resistive heating element to heat the cryogenic
fluid.
7. The device of claim 1, wherein the controller is operable to
control the treatment of the pulmonary vein wall with one or both
of the at least one electrode and the cryogenic fluid one of
alternatively or simultaneously.
8. The device of claim 1, wherein of the plurality of lumens
includes a side-viewing optical fiber within the balloon.
Description
RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. Ser.
No. 14/658,214, filed Mar. 15, 2015, which is a divisional
application of U.S. Ser. No. 13/772,472, filed Feb. 21, 2013, now
U.S. Pat. No. 8,992,514, granted on Mar. 31, 2015, which claims
priority to Ser. No. 61/602,653, filed Feb. 24, 2012, the
disclosures of which are incorporated herein by reference in their
entirety.
FIELD OF THE INVENTION
[0002] This invention relates to improvements in the field of
atrial fibrillation, including devices and methods for the
treatment of atrial fibrillation using new and improved
apparatus.
BACKGROUND OF THE INVENTION
[0003] Pulmonary vein ablation is a known surgical treatment for
atrial fibrillation (AF). Current solutions are based on a single
energy source e.g. RF, cryogenic, ultrasound, laser or microwave.
Each modality has its own advantages and disadvantages both in
terms of tissue interaction or delivery method.
[0004] In order to optimize the treatment, a uniform transmural
lesion must be created in the target tissue. Overtreatment may
result in irreversible collateral thermal or mechanical damage to
surrounding tissue which may lead to perforation or other
complications while insufficient lesion creation may not
electrically isolate the PV from the left atrium wall. With some of
the technologies available today, due to the nature of the
treatment modality, it is difficult to determine at what point the
treatment desired is sufficiently administered.
[0005] For example, in a known treatment technique using a
cryogenic fluid, the fluid is introduced into a balloon catheter
which may be positioned within the pulmonary vein (PV). From
experience and prior knowledge the operating doctor may have
determined the length of time the fluid should be in contact with
the tissue to achieve the desired ablation and creation of a lesion
in the tissue. However, this may be imprecise and can vary from
doctor to doctor and with the patient's tissue makeup. Further,
introduction of the cryogenic fluid, its withdrawal, and stopping
the creation of the lesion is imprecise given that the cooling of
the tissue is gradual and to some extent not precisely
controllable. Thus, there remains a need to provide an ablation
system that permits more precise control of the creation of a
lesion and for controllably halting the extent of the damage
created by the lesion.
[0006] Another example is the creation of a lesion using radio
frequency (RF) energy.
[0007] Typically, unlike a cryogenic solution, in the treatment of
AF using a RF source, a balloon is not used, but rather a catheter
with one or more electrodes is introduced into the PV and the
electrodes activated. Again, as in the example of the cryogenic
treatment, the duration of treatment and the extent of damage
caused by the application of RF may be imprecise and only loosely
controllable. Thus, there is a need to provide a RF ablation system
that permits more precise control and monitoring of a lesion
created by the application of RF energy.
SUMMARY OF THE INVENTION
[0008] One aspect of the invention in the present application is to
create a system which combines different modalities in a unique
structure. Based on its nature, some modalities can be used for
treatment or for measuring and diagnostic purposes in order to
monitor the lesion dimension and quality and to feedback the system
in order to optimize the treatment.
[0009] The present invention provides a device suitable for
insertion into the pulmonary vein for the treatment of atrial
fibrillation and in particular may include at least one aperture
lumen having distal and proximal ends as well as an inflatable
balloon in the vicinity of the distal end of the lumen. An optical
fiber may be positioned at least partially within the at least one
lumen; and there may be at least one opening in the vicinity of the
distal end and within the inflatable balloon. An optical device may
be placed in the lumen in the vicinity of the distal end and within
the balloon to deflect a laser beam introduced in the vicinity of
the proximal end and exiting in the vicinity of the distal end of
the lumen. At least one electrode may be formed on the balloon, and
the at least one electrode may be suitable for one or both of
measurement and treatment of the pulmonary vein. A controller may
be operatively connected to the at least one electrode, such that,
when the inflatable balloon is inflated, the at least one electrode
comes into contact with the pulmonary vein wall for one or more of
measurement and treatment of atrial fibrillation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the drawings, in which like reference numerals indicate
related parts are elements of the embodiments of the present
invention throughout the several views:
[0011] FIG. 1 is a diagram of a laser ablation balloon device in
accordance with the present invention.
[0012] FIG. 2 is another embodiment of the invention of FIG. 1 in
which there are a plurality of arrays of measuring elements.
[0013] FIG. 3 is an alternative embodiment to that of FIG. 1 which
includes a number of treatment electrodes.
[0014] FIG. 4 is a variation of the embodiment of FIG. 3 and
includes a number of cross related RF electrodes.
[0015] FIG. 5 is an alternative embodiment of FIG. 1 and includes 2
lumens, a laser lumen and a viewing lumen.
[0016] FIG. 5A is an alternative embodiment of FIG. 5 including a
laser lumen and a viewing lumen.
[0017] FIG. 6 is an embodiment related to FIG. 5 illustrating the
ability of the laser viewing lumens to rotate about an axis within
the balloon.
[0018] FIG. 7 is an alternative to the side firing laser of FIG. 1
and includes a conical shape reflector.
[0019] FIG. 8 is an improved cryogenic balloon device which
provides heat and cooling control as well as RF sensors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] RF is presently the dominant technology for PV ablation and,
as mentioned, does not require a balloon at all. RF is delivered
directly to the target tissue by coil electrodes, in a variety of
shapes, and delivered through a catheter.
[0021] Known laser ablation systems deliver the laser energy
through a side firing fiber located in a fixation balloon. Laser
ablation systems have the advantage that the interaction of tissue
to various types and wavelengths of laser beams is well-known in
the art, in terms of absorption of the heat generated by the beam
and the extent and timing of cooling of the irradiated tissue. In
addition, the use of laser beams to ablate tissue has the advantage
that the beam can be instantly turned on and off, allowing a more
precise control of the creation of a lesion and ablation than with
either the cryogenic or RF modalities. The beam may be delivered
from the inner volume of a balloon, through its wall, to the target
tissue. The beam may exit the balloon along a strip which acts as a
window. The optical window in the balloon material is, of course,
chosen so as to be transparent to the laser beam so that balloon
integrity is maintained during ablation. An example of a laser
treatment system suitable for the treatment of AF but without
measuring features or functionality is given in U.S. Pat. No.
7,137,395 entitled "Circumferential Pulmonary Vein Ablation Using a
Fiberoptic Balloon Catheter", the entire disclosure of which is
herein incorporated by reference in its entirety. One aspect of the
present invention is to create a balloon which has at least one,
but perhaps more than one, measuring element on either side of the
area of the balloon through which the laser beam passes, called
herein the treatment strip. In one configuration, two or more
arrays of such elements can be positioned from both sides of the
laser treatment strip. Each array may have one or more rows of
elements.
[0022] Each measuring element may be an RF electrode or an
Ultrasound transducer, and is embedded on the outer surface of the
balloon's wall and is wired with flexible wires also embedded on or
in the balloon. Each element has an outer surface which is
configured to create a direct contact with the tissue when the
balloon is inflated.
[0023] Turning now to the Figures, FIG. 1 shows one aspect of the
invention in which a balloon 10 with measuring elements 12 and 14
is positioned within the PV 16. A side firing fiber 18 located in
the balloon targets a tissue region 20 within a treatment strip
through the balloon. As illustrated in FIG. 1, a surface 24 is used
to deflect the beam spot from along the length axis of the catheter
to an angle to impact the surface of the PV. While FIG. 1 shows
this to be approximately 90 degrees, it is to be understood that
any suitable angle may be utilized. One structure to deflect the
beam may be to angle the face of the firing fiber to totally
internally reflect the beam out of the face of the fiber in a
direction transverse to the length axis of the catheter, although
any suitable desired angle may be chosen, as disclosed in U.S. Pat.
No. 5,772,657, entitled "Side Firing Fiber Optic Laser probe", the
entirety of which is herein incorporated by reference. An angled
mirror facing the exit of the laser fiber may be utilized to
deflect the beam. The beam spot 22 can manually or automatically
scan (by rotation) the treatment strip to ablate the PV wall.
Measuring elements 12 and 14 from both sides of the strip can also
treat tissue located between active pair of elements. It is known
in the art that electrodes of the radio-frequency type and the
ultrasonic type can be used alternatively in a measuring mode or a
treatment mode, thus enabling the ablation device of the present
invention to both measure the degree of success of ablation as well
as to operate in conjunction with the side firing laser to provide
treatment to the PV. Bipolar RF electrodes can be activated by a
system controller (not shown) in a variety of sequences (measuring
and/or treatment) to generate treatment and/or measuring vectors.
In one example, illustrated in FIG. 4, the vectors 30 can
crisscross each other and generate multiple adjacent X shapes from
RF electrodes 32 (A1-A7, B1-B7) in addition to the laser treatment.
In yet another embodiment, the multiple electrodes 32 can measure
tissue impedance changes resulting from the laser treatment or any
other treatment and to assess the size, depth or electrical quality
of a lesion. This information can be fed back to the system
controller for further treatment.
[0024] In yet in another configuration, the RF electrodes 32 may be
replaced by ultrasound transducers which in the embodiments if
FIGS. 1, 3 and 4 may measure changes in the mechanical properties
of the tissue by measuring changes of sound velocity, absorption or
reflection in different energies or frequencies of the target
tissue. Multiple elements can be used to focus ultrasound energy in
order to also achieve therapeutic threshold and to ablate tissue
ultrasonically rather than use RF energy.
[0025] Turning now to FIG. 2. FIG. 2 shows the side firing balloon
catheter 40 including a laser ablation strip 46 through which laser
energy is focused upon the PV. In the embodiment shown in FIG. 2,
two rows of measuring and/or treating elements 42 and 44 are
positioned on either side of the laser ablation strip 46 in order
to measure and/or treat the PV in conjunction with or in lieu of
the laser beam 48 from the side firing laser 50.
[0026] In addition to measuring changes in the tissue, the
ultrasound elements may be used for measuring, for example, the
thickness of the PV wall, which may aid the operating doctor to
determine the extent of treatment applied to the tissue. The
ultrasound elements may be used to measure the overall dimensions
of not only the PV but also the dimensions of the lesion(s) created
by the treatment.
[0027] In another configuration illustrated in FIG. 3, the RF
electrode array may include more than one row of electrodes in each
side of the treatment strip. As shown in FIG. 3, the inner pair 60,
62 can create an electric field which then pushes the electric
field 70 created by pair 64, 66 deeper into the target tissue 68. A
third pair (not illustrated) may be used to push the electric field
even deeper. More pairs can be utilized in order to fully cover the
PV wall. A pair of the RF electrodes, for example, can be
configured to deliver energy fluence to ablate a tissue in a
certain depth in conjunction with the laser ablation beam 72 or in
lieu of such beam or alternatively between energization of the
laser ablation beam 72 and RF electrodes 60, 62, 64 and 66. The
same pair of electrodes can then be configured to deliver
non-ablative energy and to only push deeper the ablative energy of
the next pair. Using this sequence of events can create a
homogenous lesion across the PV wall to achieve the best electrical
isolation safely.
[0028] Turning now to FIG. 5, this figure is similar to that shown
in FIG. 1 but includes a second fiber viewing lumen 80 arranged in
parallel "over-under" relationship to the side firing fiber lumen
82 for the laser beam. In this embodiment, the second side-viewing
fiber lumen 80 is incorporated that views the inside of the balloon
with an 180 degree offset from that of the side-firing fiber 82
lumen (as shown, although other angular offsets may be utilized).
However, one way to visualize the extent of lesion creation
immediately after the laser firing is to orient the firing and
viewing lumens "side-by-side" rather than in the "over-under"
relationship of FIG. 5. This is illustrated in FIG. 5A, in which
the lumens 92 and 94 sit side-by-side, the firing laser lumen being
92 and the viewing lumen being 94. When the lumen 92, 94
combination is rotated in direction 96, the laser fires through
lumen 92 and the results are viewable through lumen 94. Of course,
lumens 92 and 94 may be "in line" with one another, as shown in
FIG. 5 or "offset" from one another, as shown in FIG. 6, to be
discussed below. However, any suitable angle or orientation between
the firing and viewing lumens may be utilized.
[0029] For both of FIGS. 5 and 5A, it is to be understood that with
both the side-firing lumens and the side-viewing lumens that the
light beams are reoriented from along the lumens axis to an angle
from such axis using any number of devices described above with
respect to the embodiment of FIG. 1. As shown in FIG. 5, the second
side-viewing fiber lumen 80 includes an opening 88 in the lumen 80
which allows the light from the viewing fiber to be angled from a
position along the longitudinal axis length of the lumen to one at
an angle with respect to the lumen longitudinal axis. While the
operating doctor may wish to move the side firing laser 84 around
the periphery of the balloon in a circular motion while firing the
laser, there are at least two visualization problems. The first is
knowing where the laser is in fact firing and whether areas of the
PV sought to be treated are either not treated or treated too much.
The second is that while the operating doctor may rotate the
proximal end of the side-firing 84 fiber a given number of degrees,
due to torsional forces within the fiber itself, the same given
degrees of rotation may not translate precisely with the working
distal end of the side-firing fiber 84, again potentially providing
either over or under treatment. While the viewing lumen may be of a
conventional type, instead an optical coherence tomography (OCT)
device may be incorporated in the viewing lumen as well or instead
of the conventional type.
[0030] Thus, we have provided, in addition to the second viewing
fiber lumen 80, a series of markings 86, shown as lines in FIG. 5
for illustration only, either on the inside or the outside of the
balloon 90, that may be viewed through the viewing fiber, again
accounting for the 180 (or other) degree offset. Thus, the
operating doctor will not only be able to view the extent of the
lesion made by the use of the laser energy but will also know the
precise position of the side-firing fiber and the areas of the
lesion within the PV that require further (or less) ablation. The
markings may be marked from 0 degrees to 360 degrees or with any
other suitable scale. In addition, as shown in FIG. 6, the
side-firing laser fiber 100 opening and the viewing fiber 102
opening may be offset from one another so that the markings do not
interfere with the window within which the laser beam 104 operates.
The combined side-firing and viewing fibers may be rotated in
either direction, as illustrated by arrow 108.
[0031] In addition, due to the extent of miniaturization of
electronic elements, it may be useful to incorporate positioning
determining elements within the balloon itself. One possible
technology is MediGuide's (now St. Jude Medical) MPS imagery
technology on the distal end of the side-firing fiber to give the
operating doctor a 3D perspective of the balloon position vis-a-vis
the PV.
[0032] A further peripheral that may be utilized is a suitable
sensor such as sensor 110 shown in FIG. 6 located at the distal tip
of the side-firing fiber 120 which can interact with the
circumferentially disposed RF or ultrasound electrodes 112, 114 to
determine the location or orientation of the side-firing fiber tip
within the balloon and relative to a treatment window or within the
PV.
[0033] Yet another embodiment, illustrated in FIG. 6, to assure
accurate positioning and orientation of the side-firing fiber 120
and the treatment area is to equip the fiber with an
electromagnetically actuated manipulator 122 that controls rotation
and/or displacement of the side-firing fiber's distal end. Suitable
electrical connections may be made to a manipulation device/toggle
at the proximal end of the fiber which may be manipulated by the
operating doctor. While the electromagnetically manipulator 122 is
shown in FIG. 6 to be located just outside the balloon 124 it is
understood that it is within the scope of the invention that the
actuator 122 may be located within the balloon 124. This may be
combined with the direct visualization or the sensor 110 described
above to give the operating doctor direct positional orientation
information of the side-firing fiber.
[0034] Turning now to FIG. 7, this figure illustrates another form
of a laser fiber treatment device. While the lasers shown in FIGS.
1, 5 and 6 are side-firing devices, the laser fiber structure shown
in FIG. 7 is a 360 degree firing laser. In lieu of the flat but
angled mirror surface shown (24 in FIG. 1) in FIGS. 1, 5 and 6, at
the distal end of the fiber 200 is installed a conically shaped
mirror or reflector 202, with the apex 204 of the cone disposed to
face 206 the laser-firing fiber 200. In this manner, when the laser
beam is directed to the mirror, the beam will be reflected 90
degrees to the laser beam axis and reflected in a 360 degree
circular beam. In order to accomplish this, between the distal end
of the fiber and conical mirror is disposed a tube-like window 208
of a suitable material around the entire circumference of the tube
containing the fiber to allow the laser beam reflected from the
conical mirror to pass out of the catheter. The material chosen for
the window preferably is a material transparent to the laser beam
itself. While FIG. 7 illustrates a 90 degree reflection from the
conically shaped mirror or reflector, it is to be understood that
the cone shape or height may be chosen to reflect the laser beam at
other than 90 degrees depending on the desired orientation.
[0035] Turning now to FIG. 8, that figure illustrates improvements
to a cryogenic-based ablation system. As discussed above, one
problem with known cryogenic systems is the lack of precision that
may result in either undertreatment or overtreatment of the PV in
terms of lesion creation. In FIG. 8, to a presently-known cryogenic
balloon catheter 300, such as that made by Medtronic, two
improvements are added. The first is a series of RF or other (such
as ultrasonic) sensors 302 of the type as previously described in
connection with FIG. 2. The second is the addition of a source 312
of a heated fluid which may be introduced either through the same
lumen 304 as the cold fluid is introduced or through a second lumen
306. In addition, a third lumen 308 may be provided to remove cold
and/or heated fluid from the balloon and return it to the system.
In operation, cold fluid from source 314 is introduced into the
balloon 300 as is presently known through lumen 306. The RF or
other sensors 302 are activated to assess the lesion caused in the
PV by the application of cold fluid. Once the desired lesion has
been created or is the process of creation, the RF sensors which
are operatively connected to a system controller 310 will signal
the system controller to provide heated fluid to the catheter and
thus to the balloon to halt the ablation of the PV. The third lumen
308 may be utilized at this juncture to remove all the fluid within
the balloon return to a volume 316 in which it may be reused or
discarded. It is to be understood that the terms "Cold fluid" and
"heated fluid" are used relatively herein, inasmuch as the
temperatures of cold fluid being introduced are well established in
cryogenic devices being marketed presently. In particular, the term
"heated fluid" means fluid which is of a temperature greater than,
to any degree, to that of the "cold fluid". The ability to control
the introduction of both cooled and heated fluid also allows for
treatments in which the tissue may be alternatively cooled and
heated in order to achieve the desired treatment effect. In lieu of
a heated fluid being introduced into the balloon, the second lumen
304 may be constructed of a resistive-type heating element to heat
the cold fluid already present within the balloon. One or more
thermocouples 320 may be provided with the balloon itself and on
the balloon outside surface to determine tissue and fluid
temperatures operatively connected to and in conjunction with the
controller apparatus 310. It is further to be understood that only
the first improvement discussed above or the second improvement
discussed above may be provided on the cryogenic balloon catheter
300.
[0036] It is further to be understood that the RF or other
(ultrasound) sensors may be reversed in their function and operate
as further sources for causing ablation. For example, the PV may be
subjected to both a cryogenic treatment followed by an RF treatment
of the type discussed in connection with FIGS. 1-4 above, or vice
versa, or even an alternate cryogenic/RF treatment repeated a
desired number of times.
[0037] Finally, as mentioned, in a typical RF ablation device, a
balloon is not utilized, but rather, typically, coils with
electrodes are positioned in the PV or other desired location.
Mounting RF electrodes on the outer surface of a balloon, as shown
in various figures herein, allows direct and precise contact
between the electrodes and tissue. In addition, in such a balloon
RF ablation device, a side-viewing optical fiber of the type
described with reference to FIG. 5 may be utilized to provide
visual inspection of lesion created by the RF ablation coil.
[0038] The advantages of the invention described in this
application have been set forth in the foregoing description and in
the appended drawings. It will be understood, however, that this
disclosure is, in any number of respects, only illustrative.
Changes may be made in details including such matters as shape,
size, arrangement of parts without departing from the scope of the
present invention. The scope of the invention herein is defined by
the appended claims now following.
* * * * *